From 0568f7a2b61807e8efeb7a2f6d94da7cd3cdc0be Mon Sep 17 00:00:00 2001
From: Benno Schulenberg <bensberg@telfort.nl>
Date: Fri, 28 Feb 2020 12:52:06 +0100
Subject: [PATCH] undo: do not try to paste back an empty cutbuffer

Trying to do so would dereference a NULL pointer in copy_node().

This fixes https://savannah.gnu.org/bugs/?57915.

Bug existed since before version 2.2.0.
---
 src/text.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/text.c b/src/text.c
index de1f825d..5b312c4a 100644
--- a/src/text.c
+++ b/src/text.c
@@ -762,7 +762,8 @@ void do_redo(void)
 	case INSERT:
 		redidmsg = _("insertion");
 		goto_line_posx(u->head_lineno, u->head_x);
-		copy_from_buffer(u->cutbuffer);
+		if (u->cutbuffer)
+			copy_from_buffer(u->cutbuffer);
 		free_lines(u->cutbuffer);
 		u->cutbuffer = NULL;
 		break;